The Department of Conservation will take charge of riverbed cleanup after Fox River landfill burst open during floods.
Conservation Minister Eugenie Sage today announced DOC would replace the Westland District Council as the lead agency coordinating the rubbish cleanup.
Torrential rainfall and flooding exposed the disused landfill in late March, spreading rubbish along the coastline and riverbed. It has previously been described by Forest and Bird as New Zealand's worst environmental disaster since the Rena oil spill.
The council abandoned the clean-up last month, saying it lacked the funding and capacity to do more, but a small group of volunteers has continued to fill up to 40 sacks a day of washed-up waste.
About 50km of coastline was cleared before the end of May during a major volunteer effort.
Ms Sage said DOC would take the lead in the cleanup because of the internationally significant values of the national park and the Fox River area.
"The focus for the cleanup has now shifted to the Fox and Cook riverbeds over a distance of approximately 21km and around 1620 hectares," Ms Sage said.
"A challenging issue now is that debris dams and log jams have trapped a significant amount of rubbish along the river. Heavy machinery is required to remove these log jams, and there is significant amount of people time required to remove the rubbish from them."
However, she pointed out the decision would not set a precedent for other councils to relinquish their role.
"Landfills and their management are the responsibility of local authorities," Ms Sage said.
"The responsibility for the actual landfill and ensuring no more rubbish can be eroded into the Fox River remains with Westland District Council."
Anyone interested in volunteering to help clean-up can register online.